re the acid dip argument.... if you did strip & acid dip it, then clean it up properly, followed by a really thin coat of paint, it would save you a fair few kg, but you obviously would need to keep it in the dry to stop it rusting..
i read a story about the skoda rally team.. they were so short of funds, that they had to get really clever, so the rally shells would be put thru the acid baths on the production line time & time again to get the metal thinner to get the weight down.